Articles of footwear, e.g., shoes, boots, and sandals, have long been available. In recent times, numerous specialized types of footwear have been made available for different applications, e.g., running shoes for running and basketball shoes for basketball. Even within these areas, more specialized footwear is available. For example, long distance running shoes combine light weight and shock absorption with other features important to long distance runners, while track "spikes" provide extremely light weight and proper foot support with a spiked sole for optimal traction on track and field surfaces. Likewise, basketball shoes come in many varieties, and include those having low, mid, and high tops for differing amounts of ankle support.
In addition, other types of footwear, such as roller skates, have been developed. Recently, in-line roller skates have gained popularity and are being used for many purposes, ranging from recreational use to fitness training. An exciting and demanding aspect of recreational skating, particularly among adolescents and young adults, is so-called "aggressive" or "street-style" skating. Such skating is best characterized by acrobatic skating stunts and maneuvers, some of which are referred to as "grinding," or sliding across a surface (as opposed to rolling or skating) by engaging a portion of one or both in-line skates, usually an underside portion of a skate frame between two adjacent wheels, or alternatively, a portion of an exposed area of the sole of the skate boot, with a feature on the skating surface, such as an edge or ridge.
However, at present, in order to "grind," a pair of in-line roller skates is required, and thus the opportunities to engage in this activity are limited to those instances when one is wearing or readily has access to such skates.
The present invention overcomes this and other limitations by providing an article of footwear, including but not limited to a shoe, sandal, boot, or appliance for attachment to the any of the foregoing, or, alternatively, directly to a foot, which incorporates one or more features to allow such articles to be useful for grinding. Such articles of footwear preferably also serve the traditional functions for which they were previously used, i.e., walking, running, working, etc. As a result of this invention, those possessing such articles of footwear will have greater opportunity and freedom to grind when and where they desire.